The present invention relates to a compressor arrangement for a heat pump installation in which an electric motor is provided as the drive means for the compressor.
In such commercially available compressor arrangements, asynchronous three-phase motors are provided as the drive means. The drive power of such compressor arrangements for heat pump installations for the heating of single and multi-family houses is in the range of about 2 to 6 kW. With this order of power, surge currents are obtained which are about 30 A and more. In weak networks, brief voltage drops can occur due to such surge currents of a magnitude which are not permissible, for instance, especially if electronic equipment or lighting devices are coupled to the network. In order to keep such disturbances small, regulations often permit only a given number of switching actions, for instance, three switching actions per hour. This greatly limits the operation of the heat pump installation. Other attempts have been made in the past to reduce such surge currents by supplemental means, for instance, by lowering the voltage at the motor and at the same time relieving the pressure of the compressor. However, these measures are expensive and their effect is unsatisfactory.
Accordingly, it is an object of the present invention to develop a compressor arrangement of the type described above such that surge currents can be limited to low values without any supplemental measures.